I agree with Anon. There may be a decline in mailing list traffic, bit I'm definitely seeing an upswing on sites like the stack exchanges. It's not like you see friends on Facebook hitting each other up about the hot new listserv they found or starting a Like button for majordomo.

Makes me feel like doing my best Bill Cosby... "When I was young, we didn't even have email addresses, we had bang paths, 85 words long, uphill, both ways, and we were grateful!"